A conventional decision feedback equalizer system 100 is shown as FIG. 1. An input digital signal r(n) 102 is a trellis-encoded communication signal, such as a signal that is trellis-encoded according to an ATSC standard. The input digital signal r(n) 102 of equalizer system 100 is typically multipath contaminated. The multipath contamination is caused by multiple signal propagation paths. Multipath contamination is typically a primary contributor to intersymbol interference in information carried within a communication signal.
The input digital signal 102 is provided to a feed-forward linear filter (FFE) 104. After passing the FFE 104, the thus-filtered input signal 106 can be represented as Y(n) by the formula shown in Equation (1):Y(n)=dn+nn+isin  (1)In Equation (1), dn is the data to be recovered from the input digital signal 102, nn is white noise in the input digital signal 102, and isin is the inter-symbol-interference component of the input digital signal 102. The inter-symbol-interference component is nominally cancelled out by the decision feedback filter (DFE) 108. In FIG. 1, the DFE input 110 comes from a simple slicer 112. However, phase jitter in the output of the FFE 104 reduces the effectiveness of the DFE output in canceling out the inter-symbol-interference in the FFE 104 output.